As is well known in the art, DIP devices consisting of a body portion, and attached and depending leads connected thereto for assembly into a PCB or the like, are manufactured with the leads disposed in a particular arrangement adapted for insertion in a predetermined array or pattern of holes or sockets constituting a portion of a circuit in a PCB. DIP leads are relatively fragile and frequently are bent or distorted during handling, shipping and manufacturing operations. Ideally, DIP leads are in general parallel alignment relative to a plane P-P transverse to its longitudinal axis referred to herein for convenience of understanding "side plane" and thus leads bent or distorted in this plane will be described as side plane lead disorientation. Ideally, leads are also aligned in rows generally parallel to or at a predetermined angle to a plane A-A through the longitudinal axis of the DIP. Thus, leads bent or distorted in this plane will be described as "end plane" lead disorientation. It has been found the end plane disorientation is more common than side plane disorientation and that in these instances only correction of the end plane disorientation is necessary to yield an acceptable DIP.
Side or end plane bent or otherwise distorted leads of DIP devices in any of a multiplicity of planes will prevent their insertion into the predetermined arrays or sockets in a PCB. A need has existed in the art for apparatus which will determine the integrity of DIP leads, i.e. formation and configuration with respect to a DIP, prior to insertion on a PCB. Not only has disorientation or integrity caused problems, but means are required to overcome any erroneous dispositions of the leads. Heretofore, as an example, lead straighteners have been developed such as that described in U.S. Pat. No. 3,880,205 METHOD AND APPARATUS FOR STRAIGHTENING ELECTRONIC COMPONENTS issued Apr. 29, 1975, and U.S. Pat. No. 4,481,984, entitled ELECTRONIC COMPONENT LEAD STRAIGHTENING DEVICE AND METHOD issued Nov. 13, 1984, also owned by the Assignee of the instant application. The apparatus shown in these patents operates to correct erroneous disposition of leads and/or straighten bent leads, by applying a combing action to the leads. Devices for determination of lead integrity constitue an invention described in patent application Ser. No. 648,872, entitled APPARATUS AND METHOD FOR LEAD INTEGRITY DETERMINATION FOR DIP DEVICES, filed Sept. 10, 1984, also owned by the Assignee of the instant application. The devices and methods as shown and described in the aforementioned patents and pending patent application serve specific purposes to correct orientation of leads in DIPs. While these prior apparatus were generally effective for the purposes intended, the capacity of the apparatus is dependent on the cycling speed of the straightening mechanism.
It has been found in previous apparatus that in order to ensure a perfect DIP device, having leads that are perfectly aligned axially as well as cross sectionally, and having leads of varying angles of divergence from 0.degree. to some desired angle for the automatic handling machine or for manual insertion, that each DIP device entering the straightening machines from a client's packaging tube frequently needed individual lead correction manipulation and thereby slowing down the production rate.
A previous invention to increase the production rate was to install on existing "300" and "600" machines a scanning device that enabled the incoming DIP device to have its leads automatically, and at high speeds scanned by means of a light source, and incorporating a logic circuit, as disclosed in detail in said pending application Ser. No. 648,872. It has been found, as previously mentioned, that in most cases the percentage of DIPs that needed to be manipulated to achieve a client's maximum and minimum requirements or tolerances ran two to three percent of an entire order batch of DIPs. In addition, it was discovered that the production rate could be increased further due to the rapid functioning of the scanning system of the pending application which is capable of scanning and decision-making at the rate of about 10,000 units per hour. It was also determined that a factor which was slowing down production rate was the fact that the absolute precision generated by use of the known mechanical straightening device was not always required, and that minimum requirements of the client could be achieved by by-passing the mechanical combing and straightening device as disclosed in U.S. Pat. No. 4,481,984, and that the output of DIP handling apparatus is increased substantially by the novel forming mechanism and track switching mechanism of the present invention for lead straightening machines in the category of "600" up. The "300" class machines track switching mechanism was found to be capable, without redesign, of maintaining a high-output rate in combination with the scanning device and redesigned geometric forming station and mechanism due to the small throw of the "300" track switching mechanism.
The present invention constitutes a further improvement over such prior devices, and includes means for correcting out-of-plane lead orientation. Additionally, the present invention substantially increases in-plane lead damage detection rate and decreases substantially the potential for DIP hang-up or shingling thereby contributing to a substantial increase in DIP thru-put.
The present invention includes, in the overall machine, a novel geometric former employing flexible drive belts for propelling DIPs along a fixed track containing dimensionally adjustable detection and straightening means. The present device permits a vertical geometric alignment of the leads or a desired divergent angle (for example, 10.degree.) which may be required for automatic or manual insertion in a connecting socket of a PCB or the like.
The divergence or spread of the lead permits automatic machinery to grasp the DIP and dispose it in a pattern on a PCB or the like. For example, the automatic handling apparatus generally comprise jaw members which frictionally engage the opposing outer side faces of the rows of leads of a typical DIP device and presses the leads slightly inwardly to a position generally 90.degree. to the DIP body so that the rows on both sides are generally parallel for insertion in a socket opening in the PCB. The controlled selectively outward divergence of the leads produced by the forming mechanism of the present invention provides trouble-free pick-up manipulation by automatic handling equipment. For manual handling of DIPs the forming mechanism of the present invention may be set to align the rows at 90.degree. generally parallel relationship and includes means for compensating for "spring-back" during the forming operation. Thus the intermediate angular disposition is so controlled as to accommodate different patterns and automatic handling machinery.
It has been found that DIPs as provided by different manufacturers will differ in the number or percentage of DIPs having misalignment in one of the plural planes of significance, and currently some manufacturers produce DIPs wherein only one or two percent of the DIPs will have such misalignment of leads necessitating correction, and/or rejection, depending upon the built-in errors of configuration. The present invention, utilizing the components therein and also the scanner means in the co-pending patent application, can correct errors as determined by the scanner for integrity in a side view of a DIP as it races by, and the present device is further capable not only of forming and scanning initially but thereafter subjecting the leads to further straightening actions if required, or rejecting DIPs containing such misalignment as to be non-correctable. The present invention provides means for rejecting DIPs containing non-correctable lead distortions. Typically a speed of 10,000 DIPs per hour of so-called "600" to "300" designated DIPs can be processed by the present invention.